ox16pci958 Oxford Electrical Products, ox16pci958 Datasheet - Page 32

• Manufacturer Part Number: ox16pci958
• Description: Octal Uart With Interface
• Manufacturer: Oxford Electrical Products

OXFORD SEMICONDUCTOR LTD.
Type
Generated
Generated
Generated
Generated
Generated
Generated
Generated
Generated
Allowed
Allowed
Allowed
These values are calculated using the worst-case PCI clock period of 30 ns. 70 x T
33
5.2.
The contents of the EEPROM are used to generate a series of internal register writes in the
OX16PCI958 – the data specifies a sequence of addresses to be written to and the byte to be written.
Table 30 shows how the data in the EEPROM is organized.
After reset, the block reads the first word in the EEPROM. This word must contain the binary pattern
00010000 in its top 8 bits. The block uses this fact to work out the number of address bits required by
the EEPROM in the following reads, thus allowing a wide range of EEPROM devices to be used.
Now that the number of EEPROM address bits is known, the block knows where the data begins
within the serial stream, and it reads the first EEPROM word again. It latches the bottom 8 bits of this
word internally, and this value is used as the end-address of the data in the EEPROM.
In the next phase, the block reads word 1 through to end-address in sequence, stopping after it has
read the end-address word. It considers the top 8 bits of each word as an internal address and the
bottom 8 bits as data. The block performs a write on its internal bus interface, using the address and
data from the EEPROM word.
DS-0022 Nov 05
Address
00h
01h
02h
…
end address
1
/
3
MHz clock.
EEPROM Data Format
Signal
EECK
EECK
EECK
EECS
EECS
EECS
SBDIO
SBDIO
SBDIO
SBDIO
SBDIO
Bits 15:8 of data
sync. byte: must be 10h
internal address
internal address
…
internal address
Figure 4 EEPROM Signal Timings During Initialization
Timing
Cycle period
Low time
High time
Set-up before SK↑
Hold after SK↓
CS low time
Set-up before SK↑
Hold after SK↑
Delay to valid after SK↑
Hold after SK↑
Delay to high-Z after SK↑
Table 30 EEPROM Data Organization
External—Free Release
Min
4140
2040
2040
2040
2040
2040
2040
2040
-
-
-
Bits 7:0 of data
end address in EEPROM
data to write
data to write
…
data to write
Nom
140 x T
70 x T
70 x T
70 x T
70 x T
70 x T
70 x T
70 x T
70 x T
70 x T
70 x T
OX16PCI958 DATA SHEET
PCI
PCI
PCI
PCI
PCI
PCI
PCI
PCI
PCI
PCI
PCI
Max
-
-
-
-
-
2040
2040
2040
PCI
is 2.10 µs for a
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
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